1. When the human body is placed under physical or psychological stress - it increases the production of certain hormones - such as adrenaline and cortisol. 2. Frustration results from the blocking of needs and motives by something or someone that hinders us from achieving a desired goal. 3. These hormones produce marked changes in heart rate - blood pressure levels - metabolism and physical activity. 4. Although - this physical reaction will help us to function more effectively when we are under pressure for short periods of time - it can be extremely damagingto the body in the long-term effects. 5. Examples of physiological effects are release of epinephrine and norepinephrine - slowing down of the digestive system - expansion of air passages in the lungs - increased heart rate - and constriction of blood vessels.